Welcome to the Tomistic Institute podcast.

Our mission is to promote the Catholic intellectual tradition in the university, the church, and the wider public square.

The lectures on this podcast are organized by university students at Temistic Institute chapters around the world.

To learn more and to attend these events, visit us at to mystic institute.org.

It's really a pleasure to be giving a TI talk.

I used to do that all the time, but it's been a hot minute.

So, yeah, I'm excited.

I'm going to be talking about the medieval scholastic theologian Thomas Aquinas and what he thinks about sin.

Now, for Thomas, in order to understand sin, or really in order to understand anything, you have to go back to basic first principles.

So we'll start there.

And the place where we have to start for sin is evil, right? So Aquinas has to

contemporary ears a strangely capacious sense of evil, right? When we hear evil, we think of something

really bad, a plague, a genocide, torture. Aquinas is a bit more relaxed about evil. Evil for him

is any privation or lack of good that would be appropriate to some being, right? Any lack.

So evil can be minor, right? If a bad oyster causes stomach grief or a retired Nazi hiding out in Argentina,

or if a magnolia flower on my tree in the front yard fails to bloom, these are going to be

evils for Thomas Aquinas. The second thing to say is that evil is derivative, both ontologically

and epistemically. So evil's a lack or an absence,

but it's a lack or an absence of some form, due order, or measure. So we cannot really

understand this view of evil as privation until we say something about form in the thought of Thomas Aquinas.

So for Aquinas, being doesn't have a single account, definition, or nature. There is no sense

to be made of just being as such for Aquinas. The primary sense of being for him is a substance. A substance is

...